register, this soon resulting in hoarseness, inflammation and perhaps permanent injury of the voice.
The ordinary method of speaking of these registers as the 'chest,' 'throat' and 'head' registers is apt to be misleading, as in every case the tones are formed in the larynx and by the vocal cords, the 'head' and other names being derived from the fact that the sound seems to be more directed to these parts of the body.
The loudness of the tone is due to the force with which the air is expelled from the lungs, thus causing a greater range of vibration in the vocal cords. The question of timbre is much more complex. It is this feature which distinguishes the singing of the amateur in music from the professional, the uncultivated from the cultivated voice, and the resonant tones of the orator from the poor voice of the ordinary speaker. As already explained, the quality of tone is entirely influenced by the number of over-tones, these being due to other parts of the throat accessory to the vocal cords in voice production.
Fig. 6. Diagram of Vocal apparatus During Pronunciation of Vowel 'ah' (Seiler) Before explaining this point, we must first consider what other organs are essential in the production of the voice. The fundamental tones are made in the larynx as already explained, but these alone do not produce articulate speech; in fact, such tones are not limited to the human race. It is the peculiar faculty of articulating that distinguishes the voice of man from that of other animals. Articulation is due to other parts concerned in the organ of speech, such as the tongue, the teeth, the lips, the palate and the nostrils. Each of these has its influence in the formation of the voice, and a defect in any of these will be easily recognized by the experienced hearer.
The fundamental element of the voice is formed by the vowel sounds, the consonants, as the name indicates, simply modifying the vowel sounds. Although nominally the pure vowels are a, e, i, o and u, the vowel sounds are of far greater number. For instance, the a occurs in 'maw,' 'hat' and 'mate,' but in each it is sounded differently and the same occurs with the other vowels.
The simplest vowel is a (as in 'ah') which is sounded by vibrating the vocal cords, the sound issuing almost without obstruction, the tongue being lowered and the lips apart. If now, without any further change than to round the lips, the same effort be made, the a will be
